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In circuits using precision resistors, electronic noise becomes a significant issue. As a dissipative element, a resistor naturally generates fluctuating \"noise\" voltage across its terminals. This resistance noise is predicted by the fluctuation-dissipation theorem; it is a fundamental noise source present in all resistors and must be taken into account when designing low-noise electronic devices. For example, in a simple (non-inverting) amplifier, the gain is set using a voltage divider. The noise factor of precision resistors determines the actual resistor that should be used, as the noise voltage varies with the resistance, and any noise in the resistors of a voltage divider will affect the output of the amplifier. Although precision resistor noise is a fundamental source of noise, resistors often exhibit other “non-fundamental” sources of noise. The noise generated by these noise sources is called “excess noise”. Thick-film and carbon composition resistors are notorious for excessive noise at low frequencies. Wire-wound resistors and film resistors are much more expensive, but they are often used due to their excellent noise characteristics. Like every other component, precision resistors can also fail; the common ways in which this happens depend on their structure. Carbon composition resistors and metal film resistors typically fail as open circuits. Carbon film resistors usually fail when short-circuited. Carbon films and composite resistors will burn if too much power is consumed. This is also possible, but less likely with metal films and wire-wound resistors. Without encapsulation, wire-wound resistors will corrode. Resistors with carbon composition tend to drift over time, and overheating during soldering can easily damage the adhesive, causing it to evaporate. Various effects of resistance become important in high-resistance applications; due to the thermoelectric effect, if the two ends of a resistor are not kept at the same temperature, a small voltage difference will appear across the resistor. Voltage appears at the connection between the resistor leads and the circuit board as well as at the connection to the resistor body itself. Ordinary metal film resistors exhibit this effect at around 20 graphene oxide V/℃. Some resistors made of carbon can reach 400 ohms/°C, while those with a special design can reach 0.05 ohms/°C. In applications where the thermoelectric effect may become important, it is necessary to pay attention to things such as installing resistors horizontally to avoid temperature gradients, as well as to the airflow over the circuit board.